Treating copper ores and ores of copper and nickel.



No. 723,500. 7 I PATENTED MAR. 24, 1903. H. G. G. THOFEHRN & B. DE SAINTSEINE.

TREATING COPPER ORES AND ORES OF COPPER AND NICKEL.

APPLIOATION FILED SEPT: e, 1901.

N0 MODEL.

l ff/ 767260 3 1 THE NORRIS Psrzas 00., Pno'roumo" WASHINGTON. n. c.

U ITED STATES PATENT OFFICE.

HERMAN N GEORGES CHRISTIAN THOFEHRN OF PARIS, FRANCE, AND BERNARD DESAINT SEINE, OF WIDNES, ENGLAND.

TREATING COPPER ORES AND ORES OF COPPER AND NICKEL.

SPECIFICATION formingpart of Letters Patent N 0. 723,500, dated March24, 1903.

Application filed September 6, 1901. Serial No. 74,583. (No model.)

To all whom, it may concern.-

Be it known that we, HERMANN GEORGES CHRISTIAN THOFEHRN, a'formersubject of the German Emperor, but in 1896 having declared my intentionto become a citizen of the United States, residing at Paris, France, andBERNARD DE SAINT SEINE, a citizen of the French Republic, residing atWidnes, Lancaster county, England, have invented certain new and usefulImprovements in the Treatment of Copper Ores and Ores of Oopper andNickel, of which the following is a specification.

Ourinvention relates toimportantimprovements in the treatment of copperores and ores of copper and nickel after theyhave been freed by aprevious smelting of-their gangue, and it also relates to the treatmentand refining of raw and black copper.

Our process consists, essentially, in blow; ing simultaneously and onthe same spot of the surface of the metallic bath in a reverbatoryfurnace an oxidizing and scorifying mix ture composed of superheatedsteam, air,

silica,an iocc as ip n allyli nichlorin and sea--- salt. We insure thusa very rapid oxidation and a simultaneous scorification Within the zoneof influence dominated by the blastpipes of the matters to beeliminated, which can then be rejected from the zone of action of theblast-pipes by the mechanical effect of their blast itself. Bythis'means the blast acts constantly and directly on a surface of themolten bath, which is continuously renewed.

We have illustrated in the accompanying drawings a reverbatory furnaceby means of which our process may be carried out.

Figure 1 is a partial cross-section of said reverbatory furnace, andFig. 2 is a partial side elevation of same.

The furnace is provided on each lateral side with an opening or doorthrough which the blast-pipes a are introduced. These blastpipes areslanted withrelation to the surface of the bath, and their free endslead to a slight distance above said surface. I The blast-pipes aremounted on a hollow support I), through which steam is fed and which ismovable on bearings 0, so as to allow of parallel adjustment of saidblast-pipes. The

steam iscOnVeyed through a piped, connected to the hollow support I) bymeans of a hose 6. From said support the steam is admitted into themolten bath through the central tubesf, surrounded by the pipes a. Thesilica is furnished by the sand of a sand box or tank 9, connected tothe blast-pipe by a tube h, which is adapted to slide on a joint-piece't' for the purpose of adjustment of said blastpipe. The air is admittedbetween the central tubefand the pipe a through small openings m.Finally, valves 01. and 0 allow of mg ulating, respectively, thequantities of steam and silica admitted into the furnace.

We will now describe the application of our process to the treatment ofcoppernQres mait tesf In the treatment of copper ores and mattes the oreis first melted in a cupola or blast furnace, and the matte produced ischarged in a molten condition into our reverberatory furnaceT mixture ofair, steam, and silica is then blown on the surface of the molten bath.The quantity of silica is regulated according to the rapidity of thereaction proand m mtra rrqpr and ligand duced and to the composition ofthe lining of the furnace. If said lining is acid, as usual, thequantity of silica is regulated in order to obtain an acid slag; but ifthe liningis basic (dolomite, &c.) the quantity of silicais kept lowenough to obtain a well fluid basic slag.

The simultaneous reaction of the oxygen of the blast on the iron and ofthe silica on the peroxid of iron formed not only protects the walls andbottom of the furnace, but also produces enough heat in the metallicbath, so that a small quantity of fuel is sufficient to maintain thetemperature of the furnace. The slag produced during this stage of thework is withdrawn by tapping or by skimming, consequently lowering thelevel of the bath. Instead of working on with a constantly-decreasinglevel we generally prefer to maintain it at the same height by feedingthe bath with fresh ore or matte or preferably with already molten matteflowing from,

a cupola or blast furnace until the Whole of the bath is almost entirelydeprived of iron previously contained in it and brought to the state ofwhite metal. When the bath is thus arrived to the state of white metal,we only blow in a small quantity of silica by the blast of superheatedsteam and air just suflicient to scorify the small remaining quantity ofiron and to maintain a thin coating of slag on the surface of the moltenbath outside the active zone. We keep on blowing, so as to burn thesulfur which escapes as sulfurous acid until only metallic copperremains. If the matte contains an appreciable proportion of preciousmetals, such as gold, we withdraw by the ladle or by tapping the firsteighth to a tenth of copper reduced from the white metal, which quantitycontains almost the total quantity of the gold previously contained inthe matte. \Vhile blowing on the white metal, we have noted that theantimony and arsenic contained in the matte are eliminated almostentirely, probably on account of their combination with the hydrogen ofthe steam. However, if the proportion. of these metals is too large, weadd to the blast a little chlorin or sea-salt, which transforms theminto volatile chlorids.

In the treatment and refining of raw and black copper we proceed in thesame manner as described above in order to eliminate the impurities. Weadd, however, toward the end of the operation a little lime to thesilica in order to maintain a good clear slag. When the copperissuflicien tly cleaned and oxidized, we reduce and we pole it, as usual.

In the treatment of copper and nickel ores we operate in the same manneras above, by smelting first in a cupola or blast furnace, so

as to obtain a copper-nickel matte, then by tapping said matte into areverberatory fur- V nace, in which it is treated by the blast ofsuperheated steam, air, and silica, carrying along with it a smallproportion of lime, until the iron is eliminated. We thus obtain asulfid of copper and nickel, which is treated as usual.

Having now particularly described and ascertained the nature of our saidinvention and in what manner the same is to be performed, we declarethat what we claim is= 1. A treatment of copper ore, matte of copper andraw copper in a reverberatory furnace, consisting in blowing "into saidfurnace, on the surface of the bath, a mixture of superheated steam andair carrying along silica,

substantially as and for the purpose set forth.

2. A treatment of copper ore, matte of copper and raw copper in areverberatory furnace, consisting in blowing into said furnace, on thesurface of the bath, a mixture of-superheated steam and air carryingalong silica and lime, substantially as and for the pur pose set forth.

In witness whereof we have hereunto set our hands in presenceof twowitnesses.

HERMANN GEORGES CHRISTIAN THOFEIIRN. BERNARD DE SAINT SEINE. Witnessesas to H. G. C. Thofehrn:

EDWARD P. MAoLEAN, ANTOINE LAVOIX. Witnesses as to B. de St. Seine:

WM. PIERCE, H. WATSON.

